Many digital data display systems benefit from having an interactive display for the user to communicate with the associated computer system. These systems include video game systems, cellular phones, televisions, personal digital assistants, computers, laptops, servers, ATMs, and digital picture frames.
With the advance of technology, numerous methods of achieving interactive displays become possible. Touch-screen devices may operate to recognize and track user input. One example of a touch-screen device include a device having a substrate and a flexible film that are brought into contact or change its capacitive effect when a user touches the screen. The variation in resistances or capacitances at different locations may be detected to determine the location of the user input. Alternatively, optical touch screens may be used to detect a user input by shadow effect or other optical effect created or caused by an input object. Another technique used in interactive displays may involve the detection of surface acoustic waves travelling across a surface of detecting an input.
However, in many instances of input-detection methods, an input detection usually does not distinguish among inputs originated from different sources or designed to represent different sources. That is, many input-detection methods do not account for the possibility that multiple inputs originated from different sources, and do not identify and track inputs that originated from the same source when multiple sources are providing inputs.
Accordingly, there exists a need to recognize and track inputs from multiple sources.